def score_analyzer(scores):
    if not scores:
        return None
    if any(not isinstance(s,int) or not 0<=s<=100 for s in scores):
        raise ValueError("无效")
    average=round(sum(scores)/len(scores),1)
    max_score=max(scores)
    min_score=min(scores)
    pass_count=sum(1 for s in scores if s>=60)
    pass_rate=round(pass_count/len(scores)*100,1)

    return {
        "average":average,
        "max":max_score,
        "min":min_score,
        "pass_rate":pass_rate
    }
result=score_analyzer([85, 92, 78, 60, 55])
print(result)
